RCBC-467: Add support for vector search

[DemetrisChr]

Changes

• Added the Cluster#search method which takes a Cluster::SearchRequest object as a parameter
• Added the classes needed to construct vector search queries Cluster::VectorSearch and Cluster::VectorQuery
• Added some tests to verify the encoding of search requests to the format expected by the C++ backend
• Some general search fixes:
  - Removed an incorrect access of the operator field in MatchPhraseQuery which does not exist
  - Fixed the search row locations not being populated correctly in the search result

Results

All tests pass, including all relevant search & vector search tests in FIT